The verdict: can you vibe code Mermaid Chart?
Build a personal subset with code and AI rendering, but skip the complex visual canvas co-editing and enterprise suite plugins.
Replicating the core loop—typing Mermaid code or prompting an LLM to generate syntax and rendering it live via Mermaid.js—is straightforward. However, building the two-way sync canvas where moving a visual node rewrites the underlying Markdown AST without breaking parser state is a brutal engineering trap. For a personal-use clone, abandon the visual drag-and-drop canvas and focus on a split-pane text editor with live rendering and AI generation.
Estimated effort: 2-3 weeks part-time
What you can't replicate
- The massive open-source network effect of the core Mermaid.js ecosystem
- Production-grade two-way visual-to-code synchronization on an infinite canvas
- Enterprise plugins for Confluence, Jira, and Microsoft Office
Founded
2020
Raised
$21M
Team
10-50 employees
Cheapest paid tier
$10/mo
What Mermaid Chart does
Cloud-based diagramming and visual collaboration platform built around Mermaid.js, offering text-to-diagram generation, AI prompt assistance, a visual canvas editor, and ecosystem plugins.
Core features
- Markdown-style text-to-diagram rendering using Mermaid.js
- AI prompt diagram generation ('vibe diagramming') and repair
- Interactive visual canvas editor with two-way code sync
- Diagram templates and project organization
- Export capabilities (SVG, PNG, PDF)
- User authentication and personal workspace management
The business
Pricing
- BasicFree
- Plus$10/mo
- Premium$20/mo
Funding
$21M from Firebrand Ventures, Open Core Ventures, Irregular Expressions
Pay vs build, cumulative
Break-even at month 2 — after that, every month is money kept.
The hard parts of vibe coding Mermaid Chart
- Two-way synchronization between visual node-drag actions and complex textual AST syntax parsing
- Real-time multiplayer co-editing across a graphical canvas using CRDTs or operational transforms
- Deep enterprise ecosystem integrations (Confluence, Jira, Office add-ins, and local IDE extensions)
How to vibecode Mermaid Chart
Prerequisites
Node.jsfree
Required for running the Next.js full-stack framework and managing dependencies.
GitHubfree
Source control and deployment pipeline integration.
Anthropic API Keypay-as-you-go
Powers the natural language to Mermaid syntax generation feature.
AI coding tools
Recommended stack
| Frontend | Next.js with Tailwind CSS and Lucide icons |
|---|---|
| Backend | Next.js API Routes / Server Actions |
| Database | Turso (SQLite at the edge for storing diagrams and user state) |
| Auth | better-auth |
| Payments | None (personal use clone) |
| Other | Mermaid.js core rendering library, Vercel AI SDK for streaming LLM text-to-diagram generation, PostHog for analytics and error tracking |
Hosting & infrastructure
| Cloudflare | Hosting the Next.js frontend and edge API routes | $0/mo |
Build guide
01Project Scaffolding and Database Setup
Initialize the Next.js project with Tailwind CSS, configure Turso SQLite via Drizzle ORM, and set up better-auth for personal user authentication.
Scaffold a new Next.js project using TypeScript and Tailwind CSS. Install better-auth and configure a SQLite database connection using Turso and Drizzle ORM. Create database schemas for users, projects, and diagrams (storing title, mermaid_code text, and timestamps). Establish a clean dashboard layout with sidebar navigation for managing diagram folders.02Split-Pane Editor and Mermaid.js Integration
Build the core diagramming interface featuring a Markdown-style code editor on one side and a live-updating Mermaid.js rendering canvas on the other.
Build a diagram editor page with a resizable split-pane layout. On the left, place a code editor (using CodeMirror or Monaco) configured for Markdown/Mermaid syntax. On the right, embed the Mermaid.js rendering engine to parse and display the diagram live as the user types. Handle syntax error boundaries gracefully so the app does not crash on incomplete user code while typing.03AI 'Vibe Diagramming' Integration
Implement AI-powered diagram generation using the Vercel AI SDK and Anthropic API to convert plain text prompts or meeting notes into valid Mermaid syntax.
Integrate the Vercel AI SDK into the editor interface. Create an AI prompt modal and backend action that takes user text (e.g., product requirements or system notes), sends it to Claude Sonnet with strict system prompts instructing it to output *only* valid Mermaid.js syntax inside a code block, and streams the result directly into the code editor.04Diagram Management and Persistence
Add functionality to save, load, rename, delete, and export diagrams as SVG or PNG directly from the browser UI.
Implement full CRUD operations for diagrams connected to the Turso database. Add auto-saving with debounce on editor change. Include export controls that leverage Mermaid's rendering API to export the current diagram view as a high-resolution SVG or PNG file download.05Polish, Error Handling, and Deployment
Refine the UI styling, add keyboard shortcuts, handle edge cases in diagram rendering, and deploy the application to Cloudflare.
Polish the UI with clean dark/light theme support using Tailwind CSS. Add robust error catch blocks around Mermaid rendering calls to display friendly inline syntax warnings. Configure deployment settings for Cloudflare Pages/Workers, verify environment variables for Turso and Anthropic, and ensure zero build errors.
Cost vs paying for Mermaid Chart
What will you build it with?
Starting total with Claude Code$0 one-time
Starting costs (one-time)
- Custom domain (optional)$12/yr
Total~$12 one-time
Ongoing costs (monthly)
- Anthropic API usage for AI diagram generation~$3-5/mo
Total~$3-5/mo
Paying for Mermaid Chart
$10 - $20/mo
Your time to build
25-35 hours
AI tool credits
~$20 (Claude Pro / API credits)
Break-even
Never (built for personal learning and control)
Vibe code Mermaid Chart: FAQ
- Can you vibe code Mermaid Chart yourself?
- Solid side project — 65/100 vibecodeable. Build a personal subset with code and AI rendering, but skip the complex visual canvas co-editing and enterprise suite plugins.
- How long does it take to vibe code Mermaid Chart?
- 2-3 weeks part-time — roughly 25-35 hours of hands-on time with an AI coding agent.
- How do you build your own Mermaid Chart?
- Scoped to personal use: Next.js with Tailwind CSS and Lucide icons on the front, Next.js API Routes / Server Actions behind it, Turso (SQLite at the edge for storing diagrams and user state) for data. Follow the 5-step build guide on this page — each step has a paste-ready prompt for an AI coding agent.
- How do you code your own Mermaid Chart without being an expert?
- Use an AI coding tool (Claude Code or Cursor) and work in small steps: scaffold, data model, core screens, then deploy. Realistic effort: 2-3 weeks part-time. The prompts on this page are written so the AI does the heavy lifting.
- How much does it cost to vibe code Mermaid Chart instead of paying?
- About ~$12 one-time to start and ~$3-5/mo to run, versus $10 - $20/mo for Mermaid Chart. Break-even: Never (built for personal learning and control).
- What stack should you use to vibe code Mermaid Chart?
- Next.js with Tailwind CSS and Lucide icons; Next.js API Routes / Server Actions; Turso (SQLite at the edge for storing diagrams and user state); plus Mermaid.js core rendering library, Vercel AI SDK for streaming LLM text-to-diagram generation, PostHog for analytics and error tracking.